eu.stratosphere.nephele.taskmanager.bytebuffered.IncomingConnection.java Source code

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Here is the source code for eu.stratosphere.nephele.taskmanager.bytebuffered.IncomingConnection.java

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/***********************************************************************************************************************
 * Copyright (C) 2010-2013 by the Stratosphere project (http://stratosphere.eu)
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 **********************************************************************************************************************/

package eu.stratosphere.nephele.taskmanager.bytebuffered;

import java.io.IOException;
import java.nio.channels.ReadableByteChannel;
import java.nio.channels.SelectionKey;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import eu.stratosphere.nephele.taskmanager.bufferprovider.BufferProvider;
import eu.stratosphere.nephele.taskmanager.transferenvelope.DefaultDeserializer;
import eu.stratosphere.nephele.taskmanager.transferenvelope.NoBufferAvailableException;
import eu.stratosphere.nephele.taskmanager.transferenvelope.TransferEnvelope;
import eu.stratosphere.util.StringUtils;

/**
 * This class represents an incoming data connection through which data streams are read and transformed into
 * {@link TransferEnvelope} objects. The source of the data stream is a TCP connection.
 * 
 */
public class IncomingConnection {

    /**
     * The log object used to report debug information and possible errors.
     */
    private static final Log LOG = LogFactory.getLog(IncomingConnection.class);

    /**
     * The readable byte channel through which the input data is retrieved.
     */
    private final ReadableByteChannel readableByteChannel;

    /**
     * The {@link DefaultDeserializer} used to transform the read bytes into transfer envelopes which can be
     * passed on to the respective channels.
     */
    private final DefaultDeserializer deserializer;

    /**
     * The byte buffered channel manager which handles and dispatches the received transfer envelopes.
     */
    private final ByteBufferedChannelManager byteBufferedChannelManager;

    public IncomingConnection(ByteBufferedChannelManager byteBufferedChannelManager,
            ReadableByteChannel readableByteChannel) {
        this.byteBufferedChannelManager = byteBufferedChannelManager;
        this.deserializer = new DefaultDeserializer(byteBufferedChannelManager);
        this.readableByteChannel = readableByteChannel;
    }

    public void reportTransmissionProblem(SelectionKey key, IOException ioe) {

        LOG.error(StringUtils.stringifyException(ioe));

        try {
            this.readableByteChannel.close();
        } catch (IOException e) {
            LOG.debug("An error occurred while closing the byte channel");
        }

        // Cancel key
        if (key != null) {
            key.cancel();
        }

        // Recycle read buffer
        if (this.deserializer.getBuffer() != null) {
            this.deserializer.getBuffer().recycleBuffer();
        }

        this.deserializer.reset();
    }

    public void read() throws IOException, InterruptedException, NoBufferAvailableException {

        this.deserializer.read(this.readableByteChannel);

        final TransferEnvelope transferEnvelope = this.deserializer.getFullyDeserializedTransferEnvelope();
        if (transferEnvelope != null) {

            final BufferProvider bufferProvider = this.deserializer.getBufferProvider();
            if (bufferProvider == null) {
                this.byteBufferedChannelManager.processEnvelopeFromNetwork(transferEnvelope, false);
            } else {
                this.byteBufferedChannelManager.processEnvelopeFromNetwork(transferEnvelope,
                        bufferProvider.isShared());
            }
        }
    }

    public boolean isCloseUnexpected() {

        return this.deserializer.hasUnfinishedData();
    }

    public ReadableByteChannel getReadableByteChannel() {
        return this.readableByteChannel;
    }

    public void closeConnection(SelectionKey key) {

        try {
            this.readableByteChannel.close();
        } catch (IOException ioe) {
            LOG.error("On IOException occured while closing the socket: + " + StringUtils.stringifyException(ioe));
        }

        // Cancel key
        if (key != null) {
            key.cancel();
        }
    }
}